The overall goal is to define the properties of anti-viral CD8+ T-cells that should be elicited by an HIV-1 vaccine (preventative and therapeutic) or elicited as part of a therapeutic strategy for an HIV-1 cure. CD8+ T-cells maintain long-term control of HIV-1 viremia in virus controllers, defined as HIV-1 infected patients naturally able o control virus replication without therapy. Several genes expressed in HIV-1 CD8+ T-cells have been identified as correlating or mediating HIV-1 inhibition in controllers. However, the regulation of gene expression as well as the full repertoire of genes that mediate CD8+ T-cells' HIV inhibitory activity are unknown. This gap in the current knowledge of CD8+ T-cell antiviral responses limits the ability to develop efficacious vaccines and curative therapies that can harness the immunological protection provided by CD8+ T-cell mediated antiviral mechanisms. The Tomaras lab previously found that the antiviral CD8+ T-cell mediated response is modulated by epigenetic mechanisms, providing a new paradigm for the induction of effective CD8+ T-cell mediated inhibition of HIV-1. Moreover, our lab identified that HIV-1 vaccination elicits CD8+ T-cell mediated HIV-1 inhibition with the greatest activity found in memory cell subpopulations. Taken together, these data indicate epigenetics play a role in mediating the memory CD8+ T-cell response to HIV by allowing the transcriptional machinery access to appropriate genes when HIV-1 antigens are encountered. This project builds significantly upon recently published work using the innovative combined strategies of CD8+ T-cell virus inhibition assays, flow cytometry with cell sorting, and molecular techniques to define the genes and epigenetic regulatory mechanisms that play a role in the CD8+ T-cell response. To achieve this goal, epigenetic marks and gene expression in CD8+ T- cells, sorted from the same patient, with and without activity will be examined. Completion of the project will provide key data that will enable identification of the gene expression profiles and epigenetic mechanisms responsible for the most functional CD8+ T-cells from patients naturally controlling HIV-1 infection (virus controllers).